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  <title>Three way comparisons</title>
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  <h1 class="Head">Three way comparisons</h1>
  <p class="Para">Three way comparisons show the differences between three different versions of a resource. This
  feature is most useful when merging resources or when there is a conflict during synchronization. Conflicts occur
  when two developers add a version from the same branch to their Workbench, then each developer modifies it, then one
  developer attempts to commit the resource after the other developer has already committed it.</p>
  <p class="Para">When this situation arises, you can view the differences between three resource versions: the
  resource in the Workbench, the version of the resource that is committed in the branch, and the <i>common
  ancestor</i> from which the two conflicting versions are based. If a common ancestor cannot be determined, for
  example because a resource with the same name and path was created and committed by two different developers, the
  comparison becomes a two-way comparison.</p>
  <h2>Interpreting compare results</h2>
  <p>The Synchronize view allows you to view the differences between two or three files. If a common ancestor is
  available, the sync view performs a three way comparison. It is possible that a common ancestor for two conflicting
  resource versions cannot be determined, (e.g. a resource with the same name and path is created and committed by two
  different developers). In this case the compare becomes a regular two way compare.</p>
  <p class="Para">In a three way compare the Workbench shows you:</p>
  <ul class="UnorderedList">
    <li class="Item">what has been changed in the first child in comparison to the common ancestor.</li>
    <li class="Item">what has been changed in the second child in comparison to the common ancestor.</li>
  </ul>
  <p class="Para">In the picture below, the common ancestor is displayed in the top pane of the text compare pane. The
  differences that you see highlighted are what has changed in the Workbench resource as compared to the common
  ancestor, and what has been changed in the branch resource as compared to the common ancestor. The sections that
  differ in all three files are highlighted as differences.Conflicts are shown in red, incoming changes in blue, and
  outgoing changes in gray.</p>
  <p class="Para"><img src="../images/Image49_3_way_compare.png" alt="Synchronize View with 3 way compare" border=
  "0"></p>
  <h3 class="related">Related tasks</h3>
  <a href="../tasks/tasks-68.htm">Comparing resources</a><br>
  <a href="../tasks/tasks-115.htm">Synchronizing with a repository</a><br>
  <a href="../tasks/tasks-68dg.htm">Merging changes in the compare editor</a><br>
  <a href="../tasks/tasks-113b.htm">Resolving conflicts</a><br>
  <a href="../tasks/tasks-68b.htm">Setting preferences for comparing files</a><br>
  <a href="../tasks/tasks-101.htm">Comparing resources with repository versions</a>
  <h3 class="related">Related reference</h3><a href="../reference/ref-25.htm">Compare editor</a>
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